How to change the video's background color in Windows Movie Maker
The background color of the default video is black, but in some full-screen subtitles or non-full-screen media clips, we want the background color to be more colorful. Adjusting the background color can improve the overall appearance of the video and make it more attractive and artistic.
Change the video's background color
In the timeline, click the color button at the bottom of the preview window.
Choose one color from the color base or click “Pick Screen color” to choose the default setting color or pick up the color from the video's element.
To apply the color, click the“ok” button.
It's better drag the video to the PIP track,if the video's full cover the screen, you can zoom to it.
If the background color does not change, you can check if you have selected the video on the timeline. There will appear a yellow square frame if you pitch on the video on the timeline.
You can confirm whether the video size overlaps the background or not. If so, you could choose a color at first and then crop the video to see the video playback effect.